Improvement in blackboard-rubbers



l. F. ROENIGK.

Blackbeard-Rubber N0,11,',520l Patented Feb. 17, 1824.

UNITED STATES JOHN F. ROENIGK, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO HIMSELF PATENT OFFICE.

AND SAMUEL E. GILI-i, OF SAME PLACE.

IMPRovx-:MENT IN BLAcKBoAnn-RUBBERS.

Specification forming part of Letters Patent No.147,520, dateclFebiuary 17,1874; application filed December 23,11573.

To all whom fit may concern:

Be it known that I, J oHN F. ROENIGK, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Wipers for Blackboards; and I do hereby declare that the folp lowing is a full and exact description thereof,

reference beinghad to the accompanying drawings, and to the letters of reference marked e thereon.

The nature of my invention consists in providinga new article of manufacture, viz: A

wiper for school-blackboards consisting of a block of cork, or wood and cork combined, and covered with cloth, plush, or other suitable fabric. p

To enable others to make and use my invention, I will proceed to describe more fully its construction.

In the accompanying drawings, which form part of my specification, Figure l is a perspective View of my improved block for wiper for school-blackboards. Fig. 2 is a 'transverse section of the same. Fig. 3 represents a transverse section of the block when constructed entirely of cork. Fig. 4 is a section of covered block.

A represents the block, which may be formed entirely of cork, as shown in Fig. 3. B represents the block when formed of wood and cork combined, as represented in Fig. 2, O O representing the cork veneering of the block B. The two side edges of the block are grooved, as indicated at d, for the purpose of enabling the user to readily grasp and hold the wiper. The block is covered with cloth, indicated at e, preference being given to that article of cloth known in commerce as corduroy, having a velvety surface, or it may be cove-red with plush cloth or other suitabiefabric, the same being secured to the ends and in the grooves by the use of glue or other adhesive material. By constructing a wiper as hereinbefore described it will be light, and the face surface of the block will be soft and ilexible, which is a valuable consideration in a rubbing block, as the tendency to injure the blackboard by striking the wiper against it in the wipingprocess will be obviated. The blackboard as a general rule being painted upon plastered walls is easily injured by bringing a hard and unyielding body in contact withit. wipers, the block of which, when constructed of a hard substance, are very objectionable, for in the handsof children they are apt to injure the surface of the blackboard by striking the edges or corners of the wiper against the plastered and painted wall which forms the blackboard, but when `the wiper is constructed of soft and yielding materials, as hereinbefore described, for manufacturing my improved wiper, it is almost impossible to iu jure the surface of the blackboard in the process of wiping it by the use of such wiper.

Having thus described my improvement, what I claim is- A rubber for blackboards when the block or body of the rubber is constructed of cork, or wood and cork combined, and covered with a suitable cloth, substantially as herein described, and for the purpose set forth.

J. F. ROENIGK.

Witnesses:

En. A. KITZMILLEE, J AMES J. JOHNSTON.

Therefore, 

